/*!
 * SmartMenus jQuery Plugin Keyboard Addon - v0.1.0 - August 25, 2014
 * http://www.smartmenus.org/
 *
 * Copyright 2014 Vasil Dinkov, Vadikom Web Ltd.
 * http://vadikom.com
 *
 * Licensed MIT
 */

(function ($) {

    function getFirstItemLink($ul) {
        return $ul.find('> li > a:not(.disabled)').eq(0);
    }

    function getLastItemLink($ul) {
        return $ul.find('> li > a:not(.disabled)').eq(-1);
    }

    function getNextItemLink($li, noLoop) {
        var $a = $li.nextAll('li').children('a:not(.disabled)').eq(0);
        return noLoop || $a.length ? $a : getFirstItemLink($li.parent());
    }

    function getPreviousItemLink($li, noLoop) {
        var $a = $li.prevAll('li').children('a:not(.disabled)').eq(0);
        return noLoop || $a.length ? $a : getLastItemLink($li.parent());
    }

    // jQuery's .focus() is unreliable in some versions, so we're going to call the links' native JS focus method
    $.fn.focusSM = function () {
        if (this.length && this[0].focus) {
            this[0].focus();
        }
        return this;
    }

    $.extend($.SmartMenus.Keyboard = {}, {
        docKeydown: function (e) {
            var keyCode = e.keyCode;
            if (!/(27|37|38|39|40)/.test(keyCode)) {
                return;
            }
            var $root = $(this),
                obj = $root.data('smartmenus'),
                $target = $(e.target);
            if (!obj || !$target.is('a')) {
                return;
            }
            var $li = $target.parent(),
                $ul = $li.parent(),
                level = $ul.dataSM('level');
            // exit it if this is an A inside a mega drop-down
            if (!level) {
                return;
            }
            // swap left & right keys
            if (obj.opts.rightToLeftSubMenus) {
                if (keyCode == 37) {
                    keyCode = 39;
                } else if (keyCode == 39) {
                    keyCode = 37;
                }
            }
            switch (keyCode) {
                case 27: // Esc
                    if (obj.visibleSubMenus[level]) {
                        obj.menuHide(obj.visibleSubMenus[level]);
                    } else if (level == 1) {
                        if (obj.opts.isPopup) {
                            obj.menuHideAll();
                        }
                        if (obj.opts.keyboardEscapeFocus) {
                            try {
                                obj.opts.keyboardEscapeFocus.focusSM();
                            } catch (e) {
                            }
                            ;
                            // focus next focusable page element
                        } else {
                            var $lastMenuFocusable = $root.find('a, input, select, button, textarea').eq(-1),
                                $allFocusables = $('a, input, select, button, textarea'),
                                nextFocusableIndex = $allFocusables.index($lastMenuFocusable[0]) + 1;
                            $allFocusables.eq(nextFocusableIndex).focusSM();
                        }
                    } else {
                        $ul.dataSM('parent-a').focusSM();
                        obj.menuHide(obj.visibleSubMenus[level - 1]);
                    }
                    break;
                case 37: // Left
                    if (obj.isCollapsible()) {
                        break;
                    }
                    if (level > 2 || level == 2 && $root.hasClass('sm-vertical')) {
                        obj.activatedItems[level - 2].focusSM();
                        // move to previous non-disabled parent item (make sure we cycle so it might be the last item)
                    } else if (!$root.hasClass('sm-vertical')) {
                        getPreviousItemLink(obj.activatedItems[0].parent()).focusSM();
                    }
                    break;
                case 38: // Up
                    if (obj.isCollapsible()) {
                        var $firstItem;
                        // if this is the first item of a sub menu, move to the parent item
                        if (level > 1 && ($firstItem = getFirstItemLink($ul)).length && $target[0] == $firstItem[0]) {
                            obj.activatedItems[level - 2].focusSM();
                        } else {
                            getPreviousItemLink($li).focusSM();
                        }
                    } else {
                        if (level == 1 && !$root.hasClass('sm-vertical') && obj.visibleSubMenus[level] && obj.opts.bottomToTopSubMenus) {
                            getLastItemLink(obj.visibleSubMenus[level]).focusSM();
                        } else if (level > 1 || $root.hasClass('sm-vertical')) {
                            getPreviousItemLink($li).focusSM();
                        }
                    }
                    break;
                case 39: // Right
                    if (obj.isCollapsible()) {
                        break;
                    }
                    // move to next non-disabled parent item (make sure we cycle so it might be the last item)
                    if ((level == 1 || !obj.visibleSubMenus[level]) && !$root.hasClass('sm-vertical')) {
                        getNextItemLink(obj.activatedItems[0].parent()).focusSM();
                    } else if (obj.visibleSubMenus[level] && !obj.visibleSubMenus[level].hasClass('mega-menu')) {
                        getFirstItemLink(obj.visibleSubMenus[level]).focusSM();
                    }
                    break;
                case 40: // Down
                    if (obj.isCollapsible()) {
                        var $firstSubItem,
                            $lastItem;
                        // move to sub menu if appropriate
                        if (obj.visibleSubMenus[level] && !obj.visibleSubMenus[level].hasClass('mega-menu') && ($firstSubItem = getFirstItemLink(obj.visibleSubMenus[level])).length) {
                            $firstSubItem.focusSM();
                            // if this is the last item of a sub menu, move to the next parent item
                        } else if (level > 1 && ($lastItem = getLastItemLink($ul)).length && $target[0] == $lastItem[0]) {
                            var $parentItem = obj.activatedItems[level - 2].parent(),
                                $nextParentItem = null;
                            while ($parentItem.is('li')) {
                                if (($nextParentItem = getNextItemLink($parentItem, true)).length) {
                                    break;
                                }
                                $parentItem = $parentItem.parent().parent();
                            }
                            $nextParentItem.focusSM();
                        } else {
                            getNextItemLink($li).focusSM();
                        }
                    } else {
                        if (level == 1 && !$root.hasClass('sm-vertical') && obj.visibleSubMenus[level] && !obj.opts.bottomToTopSubMenus) {
                            getFirstItemLink(obj.visibleSubMenus[level]).focusSM();
                        } else if (level > 1 || $root.hasClass('sm-vertical')) {
                            getNextItemLink($li).focusSM();
                        }
                    }
                    break;
            }
            e.stopPropagation();
            e.preventDefault();
        }
    });

    // hook it
    $(document).delegate('ul.sm', 'keydown.smartmenus', $.SmartMenus.Keyboard.docKeydown);

    $.extend($.SmartMenus.prototype, {
        keyboardSetEscapeFocus: function ($elm) {
            this.opts.keyboardEscapeFocus = $elm;
        },
        keyboardSetHotkey: function (keyCode, modifiers) {
            var self = this;
            $(document).bind('keydown.smartmenus' + this.rootId, function (e) {
                if (keyCode == e.keyCode) {
                    var procede = true;
                    if (modifiers) {
                        if (typeof modifiers == 'string') {
                            modifiers = [modifiers];
                        }
                        $.each(['ctrlKey', 'shiftKey', 'altKey', 'metaKey'], function (index, value) {
                            if ($.inArray(value, modifiers) >= 0 && !e[value] || $.inArray(value, modifiers) < 0 && e[value]) {
                                procede = false;
                                return false;
                            }
                        });
                    }
                    if (procede) {
                        getFirstItemLink(self.$root).focusSM();
                        e.stopPropagation();
                        e.preventDefault();
                    }
                }
            });
        }
    });

})(jQuery);